Brain tumors are among the rarest diseases; therefore, the formal study of the epidemiology of brain tumors is a discipline practiced at scattered locations around the globe. The Brain Tumor Epidemiology Consortium (BTEC) was initiated in 2003 to help facilitate collaborative interactions between brain tumor epidemiologists regardless of geographical location. BTEC has grown to be a steady and strong organization, offering yearly meetings for its participants, opportunities for working group interactions, and several successfully funded consortium projects on malignant and benign brain tumors. To help enhance participation and increase accessibility of the conference to trainees and all participants, we offer a proposal to the NIH to help support the 2016 BTEC conference entitled, Immune Factors and viral interactions in brain cancer etiology and outcomes in Barcelona, Spain. This conference will help bring together established, new, and trainee investigators with a shared interest in the causes, consequences, prevention, and treatment of brain tumors, educate brain tumor epidemiologists on concepts of the immune environment of the brain and interactions of brain tumors with infectious agents, provide a forum for trainees to share their research findings, and foster the development of multidisciplinary collaborations. The conference will provide a mix of educational and informative plenary speakers, abstract presentations with a focus on trainees and junior investigators, working group interactions, and informal interactions during receptions and meals. The conference follows a long tradition of annual BTEC meetings, alternating between a North American site and a non-North American based site.